package com.xiaotu.facade;

/**
 * @author 张晓
 * @create 2020-06-23 14:50
 */
public class Screen {
    public static Screen instance = new Screen();
    public static Screen getInstance(){
        return instance;
    }

    public void up(){
        System.out.println(" screen up ");
    }
    public void down(){
        System.out.println(" screen down ");
    }

}
